I. Field of the Invention
This invention relates generally to vending machines, and more particularly to an improved apparatus for coupling product vending coils to their associated drive mechanisms to simplify the proper initial positioning of the product delivery coils following a change in the type of product being dispensed.
Discussion of the Prior Art
Vending machines are widely used in the sale of products. A typical vending machine generally includes one or more drawers which are divided into parallel trays having either an open forward or rearward facing end and a closed opposite end, the words "forward" and "rearward" being relative to the front of the vending machine itself. Located in each of the trays is a rigid open helix or coil which is adapted to be driven by a motor drive assembly or manually rotated when coinage or credit totalling the vend price for a selected item has been deposited. The products to be dispensed are loaded by a service person between adjacent convolutions of the rigid helix, and the motor or manual drive is designed to rotate that helix a predetermined number of degrees sufficient to advance the product beyond the front or rear open edge of the tray so that it will drop into a receptacle where it can be retrieved by the purchaser.
In the past, it has been the practice to mount the coil drive mechanism on the closed end surface of the tray and with a drive shaft passing through an opening in that closed end. The drive shaft itself typically has a non-circular cross-section, e.g., square, and a U-shaped mounting bracket, joined to the end convolution of the dispensing coil, has a correspondingly shaped opening in its web, allowing it to receive the drive shaft. A screw, washer and a spacer is then used to secure the bracket to the drive shaft, the screw passing through the washer, bracket and spacer into a threaded bore formed longitudinally in the end of the drive shaft.
While the above-described approach has been effective to couple the coil to its associated drive assembly, it unduly delays the service person when the time comes to refill a particular coil assembly with a product different from that which had been dispensed immediately before. To better understand the problem, it must be understood that the coil has to be properly positioned so that, given the amount of rotation imparted to it each time that the coil drive assembly is actuated, it must advance the product sufficiently to allow it to drop off the forward end of the shelf in which the coil is disposed. Different size products require different initial angular settings of the dispensing coil. With the prior art method of joining the vend coil to its drive shaft, it has been necessary for the service person to slide out the shelf assembly, remove the retaining clips, pull the coil free of its mounting bracket to gain access to the holding screw, use a screw driver or similar tool to remove the screw, the washer and the spacer, remove the mounting bracket from the end of the drive shaft, rotate the mounting bracket to its new angular position relative to the drive shaft and reverse all of the above steps to reassemble the coil to the drive shaft. It is has been found from experience that it can take up to 20 minutes by an experienced service person to properly reset a single coil upon a product change.
A need therefore exists in the art for a mechanism which will allow the vending coil in a vending machine to be more readily repositioned when it is desired to change the product to be vended via that coil. It is the principal object of the present invention to provide such a means, and one which will not be overly costly.
It is another object of the invention to provide a low-cost coupling device for joining a dispensing coil or helix of a vending machine to its drive shaft (either manual or electrically driven) and which allows the angular position of the coil to be adjusted in only a matter of seconds and without requiring any special tools or disassembly.